Thermostatic pump



J. FENTRESS THRMOSTATIC PUMP Original Filed Deo. 3. 1925 lfhwass,

Patented May 31, 1927.

atacan JAMES FEN'IRESS, OF CHICAGO, ILLINOIS.`

'rrrnaMosrrATIc PUMP.

Original application filed December', 1925, Serial No. 72,900. Divided and this" application led May 12,

1926. Serial No. 108,464.

My invention relates to improvements in pumps ot the pneumatic displacement type,

and my purpose, generally speaking, is to provide a pump of this type that is exceedingly simple in construction, cheap and easy to produce and ywhich will operate automatically, periodically, when subjected to materially varying temperatures, to supply small quantities ot' air to any place where needed. j

My improved pump is capable of a variety of uses, being particularly beneficial when used` in connection with a system employing a U-tube or similar 'gauge for indi eating the 'depth of liquid in a tank to automatically, periodically supply small quantities ot air to the system to` insure that the gauge always will indicate accurately the depth of liquid in the tank. j

Experience has shown that a system em! ploying a U-tube orV similar `gaugefor indicating; the depth ot liquid in. a tank loses its accuracy after a time due to greater eX- pansion and contraction of the air in the system, under variations of pressure," than occurs in the liquid,V which allows the liquid to creep into the system and thus destroy the accuracy of the latter; Pumps of various designs have been employed heretofore in sys tems ot the kind mentioned to drive out olf such systems any liquid which may find its way into the same, but so tar as l am aware iu all prior systenis of the type mentioned which employ air supply pumps it is necessary lo operate the pump each time it is desired to secure an accurate reading ot the gauge. By incorporating mye improved pump in a liquid measuring system ot the type mentioned, however, a system such as 1s disclosed in` my prior application 72,900 tiled December 3, 1925, 'for example, of which this application is -a division, the necessity of manually operating any part of the system is eliminated and the gauge is caused at all timos to indicate accurately the level of liquid in the tank.

My inventive idea is capable ot embodiment in diiiiereut mechanical structures, certain of which are illustrated in the accompanying` drawings, butit is to be understood that the structures shown are intended merement of my invention employing liquid valves. j

Fig. 1 illustrates, conventionally, a liquid depth indicating` system of well known form "consisting essentially ot a U-tube 10 in communication at one end with a sight gauge 12 and at its other end, through a pipe 14, with a tank 16, such, for example, as the gasoline supply tank of an automobile, said pipe 1d terminating adjacent to the bottom ot tank 16 whereby, when liquid is exhausted troni` said pipe and the latter is lilled only with air, the pressure ofj'the liquid within the tank acting against the'air conlined in pipe 14 at the open end 18 ot said pipe, will cause mercury 2O contained within U-tube 10 to seek a level in calibrated gauge 12 which will indicate the 4depth of liquid in tank 16` all. in a manner which iswell known and which needs no further explanation in so far as the present invention is concerned.

As aforementioned, experience has shown that a system ot the foregoing type loses its accuracy after a timedue to greater expansion and contraction ot the air in pipe 14;, under variations of pressure, than occurs iu the liquid in tank 16, which allows the liquid in said tank to creep into the open eri-[ 18 of pipe 14 and thus destroy the accuracy of the system. As a consequence it is necessary periodically, or whenever it is desired to determine accurately `by means ot `gauge 12 the depth ot liquid in tank 1G, to supply air to pipe 1st to drive therefrom any llquul which may have entered the open end of same, and since heretofore, iu vso far as l am aware, only manually operable means have been provided for accomplishingthis purpose, the benelits ot my improved pump became at once apparent when it is understood that same functions automatically, periodically when subjected to materially varying` temperatures, such as are readily obtainable in the vicinity ot engine 22, to supply air to pipe 14, since the necessity of manually operating any `partof they system to secure an accurate reading of gauge 12 is climinated.

My improved pump consists of a closed air containing receptaclel2flhaving an a-ir intake passage 26 controlled by a valve 28 held normally closed by a spring 305 and an air discharge passage 2i2wcontrolled e ,by` a valve 34 held noririally closed by a spring 36. rlhis receptacle may be locs Wherever e it l `will ,be :subjected` to, `nniterially varying` temperatures', for` ins rnce it `may be mountechiasshown, ,upon Vt e exhaust manifold 38 ol engiiie22, and ivlien so located it operates as lfollloivs z--Whcn therecc'ptaclc `is cold the air therein is quite densegbut ,when the receptacle is heated, as occurs for in- .itance due to.. the radiatioii 4ot heat from manilfoldw ,when engine` is Tet-ditto operation, the air in said ieceptac e is caused to expand thereby creating within 1the receptacle a pressureivhiohholds inivardly ripen-V ing valve 281e rits seatandivhich forces-` outwardly openingvalve bSopen to `peimitlthe escape `of air l'romrjthe,receptacle `thrnigh discharge passage 32. ,Whent on the other hand, the receptacleiscooled, asoccurs `for instance due tof cooling ot manifold 38 when engine 22 is stopped, the air iny said receptacle contracts, thuS Crea-ting a partial vacuum in the receptacle Whichcauses. outwardly opening valve 34: to beheld to its` seat; and inwardly opening valve 2 8 to be,.opened against the :torce of its closingcspring 30, thereby admitting air to the receptacle and restoring the air therein tonormal pressure, whereupon the pun'lp isready to lrepeat the operation just` recounted whenever the engine again is started, or` Whenever, due to any other fause, the receptacle again is heated. e e

To install my piimpin a liquiddepth iudicatin'g f-:ystenroi the Atype previously described, discharge passage 32 simplyV is connected byl means oi a pipe Mh as shown ijn Fig. 1 ot the drawings, with pipe 14 at any suitable point in said pipelf-l between tube and tank 16, andwhen so installed its automatic operation each time receptacle 2l is heated and subsequently cooled, asl'or example, each time engine y22 is started and stopped, tosuliiply4 air to pipe 14tundersutlicientcvpressureto, force therefrom any liquid that may have entered the open end 18 of said pipe is obvious. ,e y

As pipe 14; does not require acontinuous supply otair, but to the contrary requires only that a supply of air at intervals to4 assure that gauge r12Will indicate `accurately the height ofliquidin tanltlit ismanitest that the ar *angement described meets all practical requirements in a liquid depth in dicating system and at the same time eliminates the necessity of periodically, manually operating any part of the system. I desire to have it understood, however, that in illustrating and` describing my improved pump as incorporated in a liquid depth indicating system, in which capacity it possesses particular utility, I` do not thereby intend to" convey the idea that it is restricted to such use as it may be employed to advantage in" other capacities. e e l e e, order to illustrate that no particular shape or :term of receptacle 24 or of valves 28, isessential to h4my present broad inventive idea, I have shoivn in Fig. 2 another `speci h'c enibodimeiit ot'` `iny invention wherein theclosedfpiunp receptacle in the torni ol a coil of tubing 42j, ivound lor cnaiuple, around the exhaust manifold 3S. One fend of coilllis closed and the other end thereot4 is connected, toan inteiiniediate porty ot'apipe ,Llei-L Oneend o' pipe ll tei-mir` tea in a U-valve elo perlorming lill the fuuctiensL ofl valve28 by which itmiglrt barcplaced, and fthe other end of `said pipe terminates in a `U-valve` 48 perfoi'niinv` idl` the functions of valve by `vv"'l1ich itnlight be replaced.` i i e en ht of Fig, 2 is ,VEssentiallybthe arranpJ e that 1et Efi`g.,.1, "assuming that inlet passiig Washarriiinged to ctjnnnuuiicate `with ret ,L taele 2a through outlet passage ll2HbetWeen llt) the receptacle and valve ,34, the operation in u u either case being thei same.

Ul-valve 4G `is made" of` any suitable niaterial, for instance, yrubber hose, oli'` .failli-` `eiently large diameter so that the arm there- 1ot remote from pipe lll can receive and retain atiibe dhaving a small internal passage 52 terminating at the` bottom of the U- valveJ` The result is that U-valve 1G has an exceedingly small internal passage in `the arm thereof` remotefroni pipe Ll-il. entering at the bottomo'l` the U-valve a `comparatively large passage .Sellin the arin ot the `lJ-viilve that is adjacent toand connected xiv-ith pipe L14. Thevalve described can lie eouslruclrd by usingia gla s ,therlinomelerltube ashniomber 50 and a rubber tube or the like tor the external member-QG, andthe valve is `coinpleted by filling the lower portion thereof with.mercin'y` 5G. e u e `U-valvelal is identical ivith U-valve 4.6 in that it1 includes a `rubber external case having., aI tube 58 in onearrn thereejl.`pi*oviclrd with aneigceedingly smallV passage o() terniinatingatthe bottom `ot the valve in communication Withia relatively large internal passage 62 in the other arm thereojl", the valve,beingcompleted similarly to 1valve t6 by` hllingf` the `lower portion thereof `with mercury G4, lYhen connected with pipe la Ethe only?ditlerencc.betweenvalves (ld, itl is that .thevarm of valve l-t having the relatively largc passage 5e therein is connected with said pipe, nhile the arm of valve 48 having lfll) tion, a closed receptacle adapted to, be subtherein alternalely toeXpa-nd and contract,

and :L pair of U-tulbe liquid valves Connected with said receptacle, oneof said Valvesopenf ing towards seid receptacle and the other opening :muy from tllesnme.

6. n :1` thermostate pump;` in coxnblmtion7 e closed receptacle adapted to be Subjeeted to Variable tel'nperatures to cause ail' therein alternately to expand and contract, and a pair o U-nube` liquid'` Valves connected wtlr said, receptacle, ezpclr of saiclvnlves in elucllng a` pmr ol arms lmwngpnssnges therein, respectwelyof) flll'l'lerent Sizes, the

arm of one of saicl Valves that; has the smaller pase-age therem bemg connected with Saul receptacle and the erm of the other oli `Seial vulves thatlme `the larger message there JAMS FENTRESS. 

